1. Field of the Invention
The present invention relates to a sheet-material carrying device comprising a plurality of guide members for guiding a sheet material in a carrying direction.
2. Description of the Related Art
An image recording apparatus for recording an image on a sheet-shaped recording material is known. In such an image recording apparatus, the image is recorded in a scanning direction by a recorder while the recording material is fed in a sub-scanning direction perpendicular to the scanning direction. This kind of the image recording apparatus is provided with a plurality of guide members for guiding movement of the recording material to be fed in the sub-scanning direction. Meanwhile, if vibration is transmitted to the recorder from devices disposed at upstream and downstream sides of the recorder, adverse influences of image unevenness and so forth are caused. In order to prevent such adverse influences, the guide member provided on the recorder is independent from the guide members provided on the devices of the upstream and downstream sides of the recorder.
However, when the guide members are independent relative to the recorder and the anteroposterior devices thereof such as described above, a minute step exists at a joint portion of the adjacent guide members. Therefore, a posterior end of the recording material passes the step while the recorder records an image on the recording medium, and at this time, there arises a problem in that one line occurs on the image by a shock, which is caused when the posterior end of the recording material falls from the step. Although the step of the joint portion may be limited to about 0.5 mm in a conventional apparatus, it is difficult to always keep the step of 0.5 mm at a joint portion of units where the units move by ±1.0 mm due to accuracy of its parts. In order to deal with this, there is a well-known method in which a joint portion of adjacent guide members has a comb-tooth structure. By disposing the guide members so as to mesh with each other, shock is reduced when the posterior end of the recording material passes the joint portion (see Japanese Patent Laid-Open Publication Nos. 8-76299 and 8-146536, for instance).
However, even if the joint portion of the adjacent guide members has the simple comb-tooth structure such as described in the above-noted Publications, there arises a problem in that an anterior end of the recording material is caught by the joint portion when the recording materials having different sizes, different paper quality, and different curl are carried in a photographic printer and so forth. It is difficult to make all of the recording materials pass the joint portion without fail.